


Of a Different Age

by sweetiejelly



Category: Merlin (TV)
Genre: Age Difference, Alternate Universe - Canon Divergence, Light Angst, M/M, Schmoop, Temporary Character Death
Language: English
Status: Completed
Published: 2015-10-01
Updated: 2015-10-01
Packaged: 2018-04-24 05:30:28
Rating: Teen And Up Audiences
Warnings: Major Character Death, Underage
Chapters: 1
Words: 3,100
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4907281
Author URL: https://archiveofourown.org/users/sweetiejelly/pseuds/sweetiejelly
Summary: <blockquote class="userstuff">
              <p>
  <i>He’s aging about a year every two days.</i>
</p><p>(Or, Merlin accidentally spells Arthur into a baby, a fast-growing baby, and he doesn't know how to fix it.)</p>
            </blockquote>





	Of a Different Age

**Author's Note:**

> Written for the "older/younger" square of my trope_bingo card. Failing so hard at this, sorry, but wanted to get at least another fic in before the end!
> 
> p.s. I checked the underage warning but the worst of it was when Arthur was 16/17? So, not really underage in England, I think, but underage elsewhere so I thought I'd be safe.

The baby glares at him with the judgement of a thousand displeased dragons. 

“Arthur, I-” But no words follow because well, what do you say when you have spelled your king into an infant by mistake? 

Worse, what do you say when you have no idea how to change him back? 

_Shit._

~~ 

The thing about babies is that they don’t have words, just cries and screams, demands boiled down to the extremes. 

So far Merlin has puzzled out that baby Arthur likes to suck his (Merlin’s) thumb and pull on his (Merlin’s) ears. Those are the two things that make that pudgy baby face go smug, gleeful. 

The other thing about babies is that they do not grow up half as fast as this one seems to be. One day Merlin is running around warming up milk (to just the right temperature), the next day the baby’s teething, demanding Merlin’s thumbs for sucking, soothing the ache. The day after, Arthur is walking. 

It’s bewildering is what it is. 

“He’s aging about a year every two days,” Gaius remarks, remarkably calm for such an occasion. 

“He’s so cute!” Sefa coos. 

(Gwen does not know about this disaster. Gwen must _never_ know about this disaster.) 

~~ 

Arthur at two and three and five years old is tremendously cute. Merlin tries not to think of his king in this way. Arthur is a leader, a warrior, and sure, a bit of a prat but brave and honourable, and oh hell, he's bloody _adorable_. 

“Explain how your magic works.” Little Arthur crosses his arms. 

“What do you mean it just does?” 

"So you were born with it?" 

“Spells and herbs? What else?” 

“Why can’t you fix me?” 

Merlin locks himself in his room, curled up in a ball to stare at the moon. (Kilgharrah has no answers for him, saying only, “Enjoy him, Merlin. When else would you have such an opportunity to teach such a curious mind? A king?”) 

~~ 

Merlin snorts under his breath for the hundredth time that day. Leon looks so wrong-footed, trying to train young Arthur without hurting him. 

“Stop treating me like a child!” Preteen Arthur bellows at poor Leon. “It’s only this body that’s frail. I’ve not forgotten how to fight!” 

Merlin tends to Arthur’s wounds that night, the minor cuts and bruises standing out stark against the new skin. 

“You should give Sir Leon a break. He’s only trying to protect you, you know.” 

Arthur turns his petulance on Merlin. “This is your fault.” 

Merlin hangs his head in shame. It is. It is his fault. He caps the bottle of salve, his hand shaking as he does. 

Arthur sighs. “At least I’m aging fast." He catches Merlin's eyes. “I’ll catch up soon.” 

Neither of them mentions the fact that Arthur might not just catch up. He might – he might surpass his real age, wade into old age and… Merlin can't finish that thought. 

~~ 

Arthur at fifteen is a magnificent sight – so young, so golden. 

Arthur at sixteen is worse and trouble besides. Merlin walks in on him wanking in his bed and almost drops the entire tray of breakfast. (Arthur at this age also eats a lot.) 

“No, wait!” Arthur calls out when Merlin turns to go. “Just – stop. Don’t open the door. Not yet.” 

Merlin closes his eyes and tries to block out the sounds of Arthur going breathless behind him. 

But - well. 

Those moans haunt him that night, chasing his dreams until he wakes up in cold sweat and with a problem of his own in his breeches. 

“Fuck.” 

~~ 

“Teach me.” Arthur demands. 

“No!” Merlin blushes seven shades deeper. “You’re being a prat. You already know how.” 

“How to be a prat?” Arthur smiles charmingly at him and Merlin wants to give in. Almost. 

Arthur swallows though and drops his gaze, going shy. “Please, Merlin. I have my memories back but my body does not. I didn’t remember what riding a horse felt like or what a rush it was wielding a sword. I _don’t_ know how it feels to kiss someone. And I can’t very well ask Gwen now, can I? Do you- do you really not want to?” 

Merlin looks at Arthur’s fresh face, freshly seventeen. He’s beautiful but so young and Merlin feels like he’d be taking advantage. 

“Are you _sure_ you can’t ask Gwen?” 

“I want you.” Arthur looks earnest and determined and Merlin opens his mouth only to close it. 

He nods once, shaky. 

Arthur nods back. Okay. 

But neither of them makes a move, both half frozen to their spots along the table. 

“Well?” Arthur finally huffs. 

“Well what?” Merlin swivels his head to look at him. 

Arthur is blushing and glaring, such a sight in his billowy white tunic and rosy innocence. “I’m the one who needs instruction, _Mer_ lin. So, _instruct_ me.” 

Shit. 

Merlin closes his eyes and steels his nerves. He can do this. It’s just a kiss. _One_ kiss. 

Never mind that it’d be Arthur’s first kiss in this body. _Shut up._

Merlin touches Arthur’s jaw, fingers skittering up to catch in the curls at his nape. He rests his other hand on Arthur’s shoulder, bracing himself. 

Arthur leans into him, trusting, so trusting, and Merlin’s rendered defenceless. Gently, he presses a kiss to Arthur's lips, his mouth barely open, just a chaste brush. 

Arthur mimics him, and curse him but he’s a quick learner, smudging warmth all along Merlin’s insides and to the tip top of Merlin’s ears. 

Merlin opens up and captures Arthur’s lower lip between his. Arthur mirrors him, mastering this as well, making Merlin feel tingly all over, light-headed in a way he hasn't felt since Freya. 

Then comes licking. Arthur’s swell at licking, curling his tongue over Merlin’s like there are no consequences to his actions. 

(There are. Gods but there are. Especially when Arthur's hands roam hot and curious under his shirt, squeezing, touching, branding.) 

Merlin’s breathless by the time he draws back, pushes firmly with a hand on Arthur’s chest. “All right?” 

Arthur looks like he wants to argue – _no, let's do that again_ – but he doesn’t, just licks his lips and clears his throat. “Thank you, Merlin. You may go.” 

~~ 

Arthur is the age he’s supposed to be for exactly one day. 

(“But how do you know?” 

“I just – I _feel_ older, Merlin.”) 

Merlin cries himself to sleep. 

“How can he fulfil his destiny if he’s dead?” Merlin had yelled into the night sky, but the dragon had no answers for him, at least none that is useful. 

“His heart beats yet, young warlock.” 

~~ 

“I’m not dead _yet_ , Merlin. Stop moping.” 

“This is all my fault.” Merlin can’t help the quiver to his lips, the way his eyes well up. 

“ _Mer_ lin.” Arthur hops on the table and folds his hands. “Tell me more about the Druids.” 

Merlin sniffles discreetly and then blows his nose not so discreetly. Druids. He can tell Arthur about them, yes. 

“They call me Emrys.” 

~~ 

“Show me your dragon.” 

Merlin rubs at his eyes, still half asleep in his bed. “What?” He turns and sees Arthur’s silhouette in his doorway. 

“Show me your dragon,” Arthur says again. 

Merlin yawns, too sleepy to think. “That’s not some weird euphemism, is it?” 

Arthur snorts. “I’ll let you know if ah-” He clears his throat. “No, Merlin. I mean summon your big-" He pauses. "Your giant-" Arthur breaks off with a huff and drops his hands (the gesturing _really_ wasn’t helping). "The one you call Kilgharrah!" He huffs. "I would like to meet him.” 

~~ 

An hour of questioning later, no one is any more illuminated. (Even the moon has started to wane.) 

At least Merlin has the satisfaction of watching Arthur as Kilgharrah spins his riddles, giving them more and more yarn to better strangle their thoughts with. 

~~ 

Gwen finds out. Gwen is too smart not to find out. 

“Arthur!” She presses her lips together. “Why didn’t you tell me?” 

Merlin leaves them to it. His cheeks flush with the memory of the stolen kiss, how he doesn’t regret it. 

~~ 

“Gwen knows.” 

Merlin looks up from poring over the tomes for an answer and frowns. “Yes,” he says slowly. "I was there." Maybe Arthur has reached that age where his memories are starting to go. 

“No, Gwen knows about us.” Arthur arches his eyebrows significantly. 

Merlin jumps, closing the book with more force than necessary. 

From the other side of the room, Geoffrey pokes his head out, predictably, to check on the noise. 

“We’re fine!” Merlin pushes to his feet and yells at the old librarian with a little wave. 

Only, Merlin isn’t fine. “What-what do you mean she knows about us? That I have magic?” 

“That too.” 

Merlin continues to stare, wide eyed, confused. Arthur couldn’t possibly mean… 

Except apparently Arthur does. 

“She’s very understanding,” Arthur says as he steps closer, crowding Merlin against the table. “She understands that my new body, reborn as it was, is different from my old body.” 

“This _is_ your old body." 

“You’re not funny, Merlin.” Arthur tugs him up to sit on the table and slides his legs apart. 

Merlin's reaction is instant (and embarrassing). “Arthur! We’re in the library,” he hisses. 

“We’re in _my_ library, Merlin.” 

Merlin registers the hot slide of Arthur's hands up over his thighs and makes his decision. If they have Gwen's blessing… 

"Gwen really-?" 

"Yes." Arthur breathes on his neck. 

“You’re sure?” 

“ _Yes_.” Arthur bites down and _oh_. 

“The Goblin room.” Merlin scrambles off the desk and tugs Arthur along. If they are going to do this – and from the look in Arthur’s eyes, they must (and _now_ and maybe _again_ ) – then at least they can do it away from Geoffrey’s line of sight. 

~~ 

Arthur’s hair is a mess afterward. 

“Your hair’s a mess,” Merlin says, crooking his fingers through them again anyway. 

“Your fault.” Arthur noses at his neck, mouthing at a sensitive spot. 

Merlin’s shoulders slump despite the sweet rub of Arthur’s scruff against his skin. It _is_ his fault, all of it. “There must be something I can do to fix this. I can’t let you die, Arthur.” 

“Everybody dies, Merlin.” 

“But- _you_ can’t die. You heard Kilgharrah. It’s your destiny to unite Albion, to become the greatest king this land’s ever known.” 

“It's _our_ destiny to unite Albion, _together_. We have time.” 

Merlin sighs a little. Arthur has gone back to kissing him, sucking a trail of wet heat from his earlobe to his shoulder. It’s very distracting. 

~~ 

Gwen takes him aside the next day. 

"Arthur wanted to take you to his imaginary farm if he ever became a farmer, Merlin. Of course I knew he loved you too." She clutches his hand tight. "Like I loved both Arthur and Lancelot. Our hearts are not so small, Merlin. I understand." 

"I really am sorry." Merlin can't help but apologise anyway. 

"Be sorry for making him older, not for this. You _can_ change him back, can't you? Arthur said you're the most powerful sorcerer and the last Dragon Lord besides." She looks awed and giddy, his friend and his queen. 

Merlin can only nod. "I'll try my best." 

"I know you will." Gwen kisses his cheek. 

She also names him the official Court Sorcerer before the whole of Camelot, as Arthur looks on proudly. 

~~ 

Morgana shows up. Of course she does. With Aithusa in tow. 

“Well, well, well. What have we here?” 

Arthur stands tall and meets her eyes. He has Guinevere to one side, his queen, and Merlin to his other, his- sorcerer. 

“Morgana.” 

“So much grey hair,” she smirks. “It suits you.” 

Merlin secretly agrees. It makes Arthur look distinguished. 

“You heard about Merlin,” Arthur states. It’s not a question. 

“Emrys.” Morgana turns to him, awe and fear, wonder and hate all filtering through her features. 

“Yes. Father– father was misguided. Sorcery is not our enemy.” 

Morgana snaps her head back to look at Arthur. “Your epiphany comes a little late, don’t you think?” 

“I hope not too late.” 

They stare at one another, Arthur hopeful and Morgana unreadable. Merlin feels the whole court holding its collective breath. 

“Why are you here, Morgana?” Arthur finally asks. 

“I heard you were dying." 

Merlin draws in a sharp breath. Arthur is now forty-something. Or is it fifty? Merlin doesn’t like to think about it. Each day is precious. Each day is half a year of Arthur's life. 

Sometimes Merlin looks upon Gaius, with his bowed back and thinning hair, his various aches and pains, and loathes to imagine how quickly Arthur approaches the same. And still, Merlin has not found a cure to reverse the spell. 

"Not quite, as you can see." 

Morgana doesn't respond, turning instead to Merlin. "What's your game, Emrys? Why would you do this? To trick me? Did you think I would lower my guard for an old man?" 

"It was an accident." 

Morgana's expression turns manic with laughter. "The Great Emrys had an accident! You don't expect me to believe that, do you?" 

Merlin takes a deep breath and lets it out. He doesn’t blame her. Truth is, he wouldn’t believe it either. He _can’t_ believe it. All he wanted in the heat of the moment was for Arthur to understand him. How was he to know that all of _this_ would happen? That he would do something entirely new that no sorcerer has ever done before? And more to the point, that no sorcerer has ever _un_ done before. 

"No matter." Morgana turns her attention back to Arthur. "I wanted to see my brother dear and now I have." Her smile fades and the glare in her eyes hardens. 

A thick haze of smoke rises and swallows her, all swirling, gorgeous fury. When the purple clears, Morgana’s disappeared. Aithusa too. 

~~ 

"What are you doing?" 

"Nothing." Merlin doesn't stop touching the curve of Arthur's shoulder. "Thinking." 

Arthur turns. His face is no longer a surprise, how much older it keeps getting day by day – a criss-cross of wrinkles here, a stain of age spot there. 

"Do I scare you? Looking like this?" 

Merlin startles and looks into Arthur's eyes, which are as blue and discerning as ever. Merlin flashes his own eyes golden. "Do I scare _you_? Looking like this?" 

Arthur grips his wrist and kisses his knuckles. "Merlin," he says seriously, "in your bizarre, twisted, wisdom you made me a wordless babe when I was the most scared of you, of your magic, when I was the most angry that you've kept it from me all this time." 

Merlin swallows. "I didn't plan that," he mutters. 

"I know." Arthur all but rolls his eyes. "In your bizarre, twisted _magical_ wisdom. Better?" 

Merlin hums, neither agreeing nor disagreeing. His magic obviously has its own ideas. 

"Merlin," Arthur grips his free hand and nuzzles his forehead. "If I- if I don't wake up one of these days," he backs away just enough to look Merlin in the eyes, "I want you to know that I don't want you to change. I want you to _always_ be you." 

Merlin feels the sudden slick of tears on his eyelids. It’s too much – death and love all in a breath. "You _complete_ clotpole." 

By which, of course, he means I love you too, please don’t die. 

Arthur smiles and tugs him closer. 

The kiss when they collide is surprisingly sweet, sweeter even than their first kiss, even if it is a little salty too. 

"Arthur," Merlin croaks when they separate, "even if you no longer feel this way for me when you change back, I only ever want you to be _you_ , too. It was never my intention-" 

Arthur cups his cheek and curves his neck back into the kiss. 

_I know._

~~ 

Arthur stops breathing for exactly seven minutes and forty-five seconds. Then – 

“Merlin?” 

Merlin thinks he must be hallucinating. Must be. 

“Now who’s old and deaf? _Mer_ lin!” Arthur grumbles louder. 

Merlin snaps his head up. “Arthur?” He barely dares to believe. 

But it really is Arthur. He’s making a face with his young-again face. 

“Water,” Arthur says. 

“Anything.” Merlin cups his hands up to Arthur’s lips, water easy as magic dribbling down Arthur’s chin. “Are you really back?” 

“Is water really wet?” But Arthur slides a hand over Merlin’s wrist, strong and possessive and-determined. 

Merlin looks down at him, happy and confused. “What?” 

“I _died_. And came back. And I don’t even rate a kiss?” 

Merlin grins at that and let Arthur drag him down to bed, drag him down to a most enthusiastic kiss hello. 

~~ 

“What broke the spell?” Everyone asks. Even Kilgharrah wants to know. But Merlin just shakes his head, shrugs. “I don’t know.” 

“Do you really not know?” Arthur twirls a quill between his thumb and forefinger and considers him. 

Merlin crooks a small smile. “You haven’t fulfilled your destiny.” 

“No,” Arthur walks out from behind his desk, “that’s not it. You know something.” 

“I know lots of things. I keep telling you, Arthur. I have _many_ talents.” 

Arthur deliberately looks down at Merlin’s mouth, making him blush. 

Arthur just smiles at him. “Tell me, Merlin.” Arthur slides his hands down Merlin’s arms, all warmth and persuasion. “Was it true love?” 

“Really just _so_ full of yourself,” Merlin mutters. 

“ _Mer_ lin.” Arthur looks all ages all at once – innocent as a babe, patient as an old man. 

Merlin looks at him and relents. “No, that’s not it. I’ve loved you far longer than that, you prat. You came back when I wished I could trade my magic for your life.” 

Arthur looks at him, eyes wide, and his nostrils work, almost angry. “You idiot,” he says at last, completely fond as he drops a kiss to Merlin’s palm. 

That’s how Leon finds them. “Are you rehearsing poetry again?” 

“Er.” Arthur and Merlin look at each other. 

“It’s romantic?” Merlin offers. 

“Better than death,” Arthur follows. 

Leon stares at them for a beat then settles on a nod. “Queen Annis is here to see you, sire.” 

~~ 

It’s many years later, after hard-won treaties and unavoidable wars, after Albion has been united, that Arthur finds out what it is like to be with a man of a different age. 

That morning he wakes to crisp autumn air, sunshine, and a smooth-skinned Merlin looking at him from under his eyelashes, coquettish and – 

“Seventeen. We shared our first kiss when you were seventeen, remember?” 

Arthur smirks and tugs him closer. “How could I ever forget?” 

They barely make it out of bed all morning, but it’s peace time. They can afford a morning in bed reminiscing. 


End file.
